The bill is finally coming due. After years of free-wheeling application of pesticides and fertilizers by agricultural businesses and the profligate consumption of water by consumers, the Honolulu Board of Water Supply (BWS) and its ratepayers are facing a multi-million dollar tab to cover the construction of treatment plants, new wells, and a desalination facility.
In the last few months, the BWS has:
- Announced plans to put into service a well in Waimanalo to replace one taken out of service in 1994 after being contaminated by the cancer-causing herbicide Lasso (alachlor). Estimated cost: $2.5 million (not including planning and design or drilling costs);
- Published an environmental impact statement for construction of a desalination facility at Kalaeloa designed to treat 12 million gallons a day of salt water (yielding 5 mgd of potable water). Estimated cost: $45 million.
- Moved forward with the installation of a treatment plant to remove high levels of nitrate, the result of over-fertilization of Central O`ahu crops, from water drawn from the Kunia Wells II complex. Estimated cost: $5.23 million.
Living Within Means?
These projects, especially the desal plant, reflect a new approach by the Board of Water Supply toward addressing its charge of providing water to O`ahu residents. Clifford Jamile, manager and chief engineer of the BWS, said in January that the approach to serve leeward O`ahu needs through a desalination plant grew out of a failed integrated resource planning (IRP) effort – an approach to managing resources that looks at conservation in addition to new resource development. About three years ago, the state Commission on Water Resource Management prodded the four county municipal water boards to pursue IRP approaches.
But “the IRP has not got anywhere,” Jamile said at a conference sponsored by the University of Hawai`i’s Water Resources Research Center, “so now we’re taking it to communities, building consensus one community at a time.”
With watershed protection as the central guide, Jamile continued, the goal is “less water transport, more alternative sources. We develop a plan for each district. Certain interdistrict transfers will still need to occur, but the Board of Water Supply is pursuing ahupua`a-based water plans.” In the past, the agency’s approach to water delivery was to develop a unified system that could take water from virtually any well in the island and deliver it wherever the need occurred. But responding to the growing resentment of some windward residents opposed to such out-of-watershed transfers, the Board of Water Supply has abandoned that push, Jamile said.
“John Reppun said each district should live within its means,” he said, referring to one of the leaders of the Waiahole community on windward O`ahu, where water issues have been hotly contested. “We finally got the message,” he added.
“We’re creating a sustainable future. The Board of Water Supply is committed to this, with an emphasis on reuse, desalination, and renewable energy.” The desal plant at Kalaeloa, he said, may eventually be expanded from the initial 5 mgd of treated water to 35 mgd. In addition to the desal plant, he said, his agency is looking at installing a water recycling plant at the Honouliuli wastewater treatment facility and perhaps adding an ocean-thermal energy conversion plant that would produce fresh water as well as sufficient energy to run the plant.
Freshwater obtained through desalination is more expensive than that pumped from underground sources. Jamile acknowledged this in responding to the concerns of Jeff Mikulina, director of the Sierra Club, Hawai`i Chapter. “Compared to groundwater, desalination is more expensive,” Jamile wrote in an August 2002 letter to Mikulina. “However,” he continued, “new, more efficient technologies reduce costs and operational costs savings from the ongoing BWS reengineering and downsizing efforts” – i.e., layoffs – “are expected to provide sufficient cost savings, such that water rate increases will be minimized.” The environmental impact statement says it will cost between $5.5 million and $6 million a year to operate the plant at the 5 mgd level.
Assuming the plant will have a 15-year life (a desal plant built by the state at a nearby site was operational for less than four years), annual capital costs come to $3 million. If the city pays for the plant with bonds, the interest payments would probably at least double that. Add to that annual operational costs of $6 million. All totaled, it will probably cost the Board of Water Supply about $13 million a year to pay for the plant and the 1.8 billion gallons of water it is supposed to produce annually. That translates to a cost of half a cent per gallon.
It may not seem like much to purveyors of Perrier, but if you buy water in bulk, it adds up. Half a cent a gallon comes to $5 per thousand gallons (the unit used by the BWS in figuring customers’ bills). That is more than twice the basic rate of $2.17 per thousand gallons that the BWS will be charging its customers when its new rates go into effect July 1. Or, to put it another way, if a customer’s only source of water were the desal plant, and if the Board of Water Supply’s bill reflected the true cost, instead of the monthly bill coming in around $28, it would be more than $66.
Nitrates
The contaminants in Honolulu’s most important body of drinking water, the Pearl Harbor aquifer, have been widely publicized over the years. The worst of them derive from wicked, long-lived, pesticides such as DBCP and EDB used decades ago on the pineapple fields of Central O`ahu.
Now another set of contaminants – nitrates — is approaching the maximum levels allowed by the Environmental Protection Agency to protect human health. To strip these from the water pumped deep from the Pearl Harbor aquifer, the Honolulu Board of Water Supply is planning to build a plant to remove nitrates from water taken from the Kunia Wells II (after that water has passed through a granular-activated carbon treatment system to remove other contaminants). The denitrified water will then be mixed with untreated water (four parts treated to one part untreated) before entering reservoirs and water mains.
The estimated total cost of the facility is $5.229 million, with the single most expensive element a 5 million-gallons-a-day ionic exchange processor. (A year ago, the cost of the project was just $3.99 million.) If the permitting process, already under way, proceeds smoothly, construction may begin later this month.
While the removal of nitrates from groundwater is a straightforward process, the presence of the contaminants in groundwater reflects a much more complicated and gradual development. The Board of Water Supply’s environmental assessment for the project notes that “traces of nitrate have been detected in the groundwater pumped from the Kunia well fields in recent years,” a fact it attributes to “the relatively long history of fertilizer, insecticide, and pesticide usage in nearby agricultural fields.” It added, “Nitrogen from synthetic fertilizers is the most notable nitrate source in groundwater contamination.”
The maximum contaminant level for nitrates set by the EPA is 10 parts per million (ppm). The maximum nitrate concentration found in the Kunia-Waipahu area is 7 ppm. According to Jamile, chief engineer for the Board of Water Supply, “Due to the complexity of health effects from a variety of water quality constituents, BWS implements a policy of providing treatment when levels reach half of the EPA maximum contaminant levels.”
When an early draft of the environmental assessment for the project was circulated in 2003, John Harrison of the University of Hawai`i’s Environmental Center, questioned whether the public should be paying for the facility, since the problem resulted from the actions of privately owned plantations. “While we acknowledge the problematic nature of source identification,” Harrison wrote, “compensation should be sought.” Jamile’s response: “At this time, the BWS does not plan to seek compensation.”
According to the environmental assessment, the Board of Water Supply expects nitrate levels in Central O`ahu to increase “as more nitrates trickle through into the groundwater.” Although the land immediately surrounding the Kunia II wells is vacant now, Jamile told Harrison, “we disagree that large-scale agriculture has ceased in the area. The lands remain zoned for agriculture and we expect agriculture operations to increase in the future.”
The past use of synthetic fertilizers probably was responsible for placing so much nitrogen in Central O`ahu soils, as Jamile suggests. However, another force may be at work in the release of that nitrogen (in the form of nitrates) from the soil into the groundwater.
According to soil scientists at the University of Hawai`i, the soils in Central O`ahu, which are mostly acidic, retard the movement of nitrate in the subsoil. That’s good for groundwater quality, since it means that the nitrogen that is not taken up by plants is held by the soil instead of dropping straight through to the aquifer.
Acid soils are great for growing pineapple and sugar, to a lesser extent, but with most other crops, the soil’s pH needs to be raised, something that is accomplished usually by plowing lime or calcium sulfate into the ground. “Sure enough,” soil scientist Jonathan Deenik told Environment Hawai`i, “we find that as you raise the pH, the adsorption capacity of soils” – their ability to hold nitrates – “dropped dramatically.”
This may not have immediate effects; as Deenik notes, the distance between the surface and the groundwater, known as the vadose zone, may be as deep as 300 meters. But as the chemistry of the top layers changes, the likelihood increases that the acidity of the subsoils will eventually change as well and that the nitrates, held in place by the positively charged, acidic subsoils, will be released to the groundwater.
According to Ali El-Kadi, there is “quite a large reservoir of nitrate in the subsoil” of Central O`ahu. “It might be wise to monitor.”
Other O`ahu wells have shown high levels of nitrate. Waimanalo Well I tested at 7.3 parts per million at the time it was removed from service in 1994. Wells around the Kunia area have shown levels of nitrate approaching or exceeding the halfway point of the maximum contaminant level that the Board of Water Supply says it uses to decide when to treat. These include Kunia Wells I, with a maximum nitrate level of 5.3 ppm; Ho`ae`ae Wells, with 5.6 ppm; and Waipahu Wells II, with 6.5 ppm.
Lasso
The same year that Hawai`i became a state, the Honolulu Board of Water Supply started pumping water from two wells in Waimanalo. Waimanalo Well I was at a relatively low elevation – about 130 feet above sea level. Well 2 was on higher ground. For the next 35 years, the two wells provided Waimanalo residents with their drinking water.
In 1992, the federal Environmental Protection Agency began requiring water providers to test for the presence of alachlor. Following a rule-making process lasting three years, the EPA had concluded that alachlor in drinking water posed such a serious threat to health that it was all but intolerable and set maximum contaminant levels at 2 parts per billion. To get an idea of the proportion, imagine an Olympic-sized swimming pool filled with water. If a drop of alachlor were put into the pool, that would be roughly the equivalent of the maximum contaminant level allowed by the EPA. Alachlor, a restricted-use herbicide better known by its trade name Lasso, has been linked in studies on animals to cancer, liver damage, damaged red blood cells, eye lesions, and other health effects.
After one year of testing (four tests), the Board of Water Supply quietly abandoned Waimanalo Well I. At the time the well went out of service, in February 1994, the concentration of alachlor stood at 2.1 parts per billion (or micrograms per liter). According to a news report at the time, when the well was shut, it had been back in service for about a month following a 2ý year renovation of the well station. Then state Deputy Health Director Bruce Anderson was quoted as having reassured the residents, “We do not believe there was a significant increase in cancer risk.” The well had been in use for some 30 years, although no records exist as to when the Lasso contamination started.
Lasso, introduced in the 1970s, is one of the most popular herbicides used on corn and other truck crops grown in Waimanalo. According to the state Department of Health Safe Drinking Water Branch, Waimanalo Well I is the only well in the state where alachlor has been detected.
— Patricia Tummons
Volume 13, Number 11 May 2003
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